Airfoils are utilized for a variety of purposes. For example, aircraft include airfoils in the form of wings that, among other functions, provide lift for the aircraft. Airfoils, such as wings, may include flaps that are configured to be repositioned in order to alter the aerodynamic performance of the airfoil. For example, a wing may include a flap positioned along its trailing edge. During the cruise phase of a flight, the flap may be positioned so as to provide a relatively continuous surface with the remainder of the airfoil body. However, the flap may be deployed by being rotated downwardly in other phases of the flight, such as during takeoff and landing, in order to alter the aerodynamic performance of the wing.
Wings may be formed of wing panels. At least some wing panels are formed of a composite material, such as a carbon fiber composite material. Wing panels formed of a composite material may support significantly higher fatigue stresses, thereby permitting the depth, e.g., thickness, of the wing to be substantially reduced. Additionally, wings have tended to become more aft-loaded. Thus, the trailing edge device loads and the forces required to actuate flaps along the trailing edge of a wing have not experienced a linear increase as aircraft design has evolved, but, instead, the trailing edge device loads and the forces required to actuate trailing edge flaps have been more greatly multiplied as the result of the decrease in the depth of the wing and the trend towards more aft-loaded wings.
Flap support mechanisms, such as cantilevered steel tracks or truss mechanisms, configured to controllably position the flap relative to the remainder of the airfoil body have generally resolved the bending moment of the cantilevered flap as a vertical couple. The vertical couple acts at the rear spar and at a tension fitting forward of the rear spar. In many instances, the flap support mechanism is fairly substantial in order to accommodate the increases in the trailing edge device loads and the forces required to actuate trailing edge flaps such that the flap support mechanism extends underwing by a substantial distance. The wing may include a fairing to house the flap support mechanism that correspondingly protrudes a substantial distance underwing, thereby impacting the aerodynamic performance of the wing.
The wings of some aircraft utilize a drooped hinge. A drooped hinge utilizes a fixed underwing beam to create a pivot point and an actuator arm to push the trailing edge flap in the aft direction. This mechanism partially resolves the cantilever moment as a horizontal couple, rather than a vertical couple. However, this mechanism generally requires greater actuation forces as a result of the shorter moment arm. Additionally, this mechanism resolves the cantilever moment from the hinge point as a vertical couple with the underwing beam.